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Ferrite Thickness Monitoring by Measurement of Reluctance of Magnetic Circuit

IP.com Disclosure Number: IPCOM000050739D
Original Publication Date: 1982-Dec-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Burr, P: AUTHOR [+2]

Abstract

The thickness of a thin ferrite component during, for example, lapping is monitored by bridging the gap of a horseshoe magnetic recording head with the ferrite component and measuring the output voltage from the head induced by a predetermined constant voltage input signal.

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Ferrite Thickness Monitoring by Measurement of Reluctance of Magnetic Circuit

The thickness of a thin ferrite component during, for example, lapping is monitored by bridging the gap of a horseshoe magnetic recording head with the ferrite component and measuring the output voltage from the head induced by a predetermined constant voltage input signal.

The voltage generated in the 'read' windings of a magnetic recording head when a known signal is applied to the 'write' windings depends on the coupling between the two sets of windings. If, as is usually the case, the windings are on opposite legs of a horseshoe head, the voltage generated depends largely on the reluctance of the head gap. This gap reluctance is reduced, and hence the 'read' winding voltage is increased, if a highly permeable material is placed across the gap. The thicker the material the lower the reluctance and the greater the induced voltage. Hence, monitoring the induced voltage during thinning of the material across the gap gives a direct in-process indication of the thickness of the material.

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